Feank mooee



(No Model.)

F. MOORE.

INOANDESOENT ELECTRIC LAMP.

Patented Sept. 11, 1888.

WITNESSES:

N, PETERS Photmbmographer, Washington. D c.

UNITED STATES PATENT Grates.

FRANK MOORE, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO GEORGE.IVESTINGHOUSE, JR, OF SAME PLACE.

INCANDESCENT ELECTRlC LAMP.

EPECIPICATION forming part of Letters Patent No. 389.526, datedSeptember 11, 1888.

(No model.)

To all whom it may concern.-

Be it known that I, FRANK Moonn, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented or discovered a certain new and usefulImprovement in Incandescent Electric Lamps, of which improve ment thefollowing is a specification.

The object of my invention is to provide an incandescent electric lampin the illuminating action of which the rays of light evolved from itsincandescing carbon shall be thoroughly and effectively moderated anddiffused; to which end my improvement consists in an incandescentelectric lamp having a facing of fragments of transparent or translucentmaterial secured by soluble glass to its bulb.

Theimprovcment claimed is hereinafter set forth.

In the manufacture of incandescent electric lamps as heretoforepracticed it has been sometimes proposed to reduce and diffuse to somedegree thelight evolved from the incandescing carbon by rendering thebulb of the lamp partially opaque by grinding or corresponding abrasionby a sand blast or by covering the bulb by a separate inclosing-easing,the surface of which is formed of a series of lightdii'fusing faces orprojections.

My improvement is designed to attain the same result in a more thoroughand economical manner, and presents the further advantage of enablingthe bulbs to serve as shades in addition to their ordinary function ofenvelopes for the incandescing carbon filaments, thereby diffusing thelight and increasing its useful effect, while moderating its intensityand dazzling action.

In the accompanying drawings, Figure 1 is a View in elevation of anincandescent electric lamp in which my invention is applied; and Fig. 2,a partial section, on an enlarged scale, through the same.

In the practice of my invention the carbon filament 2 is inserted in thebulb 1, which is exhausted and sealed in the ordinary manner. The outersurface of the bulb is then coated with a wash or film of solution ofsilicate of soda or soluble glass, forming a transparent and adhesivebase for the connection of the Iightdiffusing medium. A facing, 3,composed of small angular fragments of transparent or translucentmaterialas crushed glass. porcelain, or the likeis then applied to andspread over the coating of soluble glass while the same is yet liquid,and upon the setting or hardening of the coating will be securely fixedthereby to the bulb l. The facing 8 completely surrounds theincandescing carbon 2 and acts as a series of facets or prisms to refract and diffuse the rays of light evolved therefrom, as indicated inthe enlarged sec tion, Fig. 2.

The salient feature of my invention consists in the employment of a baseor attaching medium for the light diffusing material which shall notonly possess the qualities of transparency and adhesiveness when firstapplied, but shall also be infusible under any degree of heat to whichan incandescent electric lamp is subjected in normal service and insoluble in water, so as to be unaffected by the contact thereof or byatmospheric moisture. I attain by the adoption of soluble glass,whichsatisfactorily complies with the requirements above stated, a resultwhich would be wholly impracticable with the use of varnish, gum, orother analogous adhesive substances, which have been heretofore proposedas cements in decorating the rear or inner surfaces of articles of glassby attaching thereto a backing of fragmentary mineral substances.

The manufacture of incandescent electric lamps under my inventioninvolves only an inconsiderable increase of cost over that of lamps ofthe ordinary construction, and the character of the operation is suchthat no risl: of injury or breakage of the bulbs is sustained. Itaffords, in addition to its action in moderating and diffusing thelight, a novel and tasteful ornamentation for the bulb, and will befound particularly advantageous by reason of the fact that thecomparatively intense light of the carbons renders a shade of somedescription materially desirable, while the short life of the bulb doesnot justify any substantial expense in that regard.

I am aware that it has heretofore been pro posed to ornament glassshades, globes, &c., in the process of manufacturing the same byattaching particles of broken glass thereto by fusion, then cracklingthe glass by immersion in cold water, and finally reheating and fornring the article into the desired shape.

I an] further aware that it is not new to attach powdered glass to thesurface of sheets of glass by first causing it to adhere thereto by gumor cement and thereafter fusing or vitrifying it to the sheets. Articlesof such character, which I hereby disclaim, differ both in their methodof manufacture and in their finished state from incandescent lamps inaccordance with my invention, the latter being formed without theapplication of heat in the connection of the facing, and thereby beingexempt from risk of fracture of the bulb, and the structure of the bulbnot being in any wise affected by the facing or its connecting medium.

I claim as my invention and desire to se cure by Letters Patent-- In anincandescent electric lamp, the com- 20 bination of a bulb, a facing offragments of transparent or translucent material, and a coating ofmaterial infusible at the maximum temperature to which the lamp isexposed and insoluble in water, said coating securing the 25 facing tothe outer surface of the bulb, sub stantially as set forth.

In testimony whereof I have hereunto set my hand.

FRANK MOORE.

\Vitncsses':

J. SNoWDEN BELL, R. H. \VHITTLEsEY.

